Hydroforming is a process, which principally is used for manufacturing components of metal which many times have a complicated geometrical shape. A conventional tool for hydroforming consists of two tool halves which are movably arranged in relation to each other between an open state and a closed state. At least one of the tool halves is provided with a recess in which it is possible to apply a blank to be worked. In the closed state of the tool halves, the recess is closed and the blank is formed by the surfaces of the recess by means the introducing of a liquid under high pressure.
When a liquid with such a high pressure is accumulated in the closed recess, large forces are required to hold the tool halves together. Usually, very large presses are used for generating the necessary forces. Such presses also require auxiliary equipment, such as, among other things, a foundation for sustaining the large forces generated by the presses. Therefore, very large capital investments are required in order to have and/or use such presses for holding the tool halves together during a hydroforming process.
WO 01/36123 shows a hydroforming device for holding the tool halves together during a hydroforming process. The hydroforming device comprises an aggregate with clamps having wedge-shaped recesses by which they press the tool halves together from opposite sides during the hydroforming process. By means of such clamps the required forces are provided for holding the tool halves together during a hydroforming process in a relatively simple manner and without the need for using large presses. The clamps are arranged at equal distances along substantially the whole long sides of the tool halves. Thereby the accessible space is restricted for, for example, a robot which applies blanks in the tool and picks out formed details.